You finally did it. You made the decision to move to Exchange Online. That was the easy part. Now you have to decide how to get your data to Exchange Online.
Some important questions to ask yourself:
Where am I migrating my mail from? An older version of Exchange? A hosted solution?
What am I going to do with PST files? Do I even want to move that data?
What about archived data?
There are plenty of ways to get your email data to Exchange Online, the best answer depends on a combination of factors, including:
What version of Exchange (if any) you are migrating from
How many mailboxes are being migrated
How important sharing free/busy calendar information is during the migration
Where archived data is stored
If you are using a unified communications solution
Before you dive off the deep end and start performing a migration, it’s important to review your scenario and define a migration strategy that makes sense for your environment and timeline.
Some important points to consider are:
If you are running Exchange 2003 or Exchange 2007, you have the option to do a staged migration without implementing a hybrid server. That’s right, both Exchange 2003 and Exchange 2007 allow you to migrate mailboxes in batches, over a period of time. This migration method does not require a hybrid deployment of Exchange. The downside – free/busy information is not shared between on premise servers and Exchange Online. Sadly, Exchange 2010 does not support a staged migration. If your requirements are to move users to Exchange Online in groups, you must implement a hybrid server in your environment.
A cutover migration really isn’t as difficult as it sounds. During a cutover migration data is synchronized in the background between the on premise Exchange server and Exchange Online. This background synchronization can occur over a period of days or weeks. This method allows you to synchronize data between the two environments until you are ready to schedule your cutover date.
A hybrid deployment of Exchange can be necessary if you have a lot of mailboxes that must be migrated over an extended period of time. A hybrid Exchange server is also necessary if your organization requires free/busy calendar information to be shared between your on premises and Exchange Online environments.
Migration tools are great, but they don’t replace experience. There are a lot of really good migration tools out there, we have used most of them. Each works well in a different scenario, but no one migration tools is a cure all for your mailbox migration and none replace proper planning.
There are a lot of scenarios for migrating to Exchange Online. With proper planning, migrating to Exchange Online can be done quickly, easily, and with minimal impact to your users.